The present disclosure relates generally to physical vapor deposition and, more specifically, to a system and methods for applying a coating directly to an interior surface of an object via cathodic arc deposition.
At least some known physical vapor deposition processes vaporize and deposit a target material onto surfaces of a workpiece to form a coating thereon. For example, in physical vapor deposition processes such as cathodic arc deposition, current is supplied to, and an electric arc is struck on a face of a target cathode to vaporize the target material from the face of the cathode. The vaporization of the cathode forms a cloud of highly ionized material that substantially fills an interior of a vacuum chamber. The coating is then formed on the workpiece by allowing the cloud to contact exposed surfaces thereof.
Generally, vaporization of a cathode in a vacuum environment forms a substantially uniform coating on the exposed surfaces of the workpiece. More specifically, at least some of the surfaces of the workpiece may be shielded such that only the exposed surfaces receive a coating thereon. However, the cloud of coating material will also deposit on an interior surface of the vacuum chamber. Moreover, cathodic arc deposition is a line-of-sight process such that only surfaces exposed to the cloud of coating material receive a coating thereon. As such, it is difficult to ensure that the coating material deposits on hard-to-reach surfaces of a workpiece, such as an interior surface thereof.